The First Part.

some of them, stick to the vaulted Roofs of the Furnaces, in the form of little and (for the most part) White Bubbles, which therefore the Greeks, and, in Imitation of them, our Drugsters call Pompholix: and others more heavy partly adhere to the sides of the Furnace, and partly (especially if the Covers be not kept upon the Pots) fall to the Ground, and by reason of their Ashy Colour as well as Weight were called by the same Greeks σποδος, which, I need not tell you, in their Language signifies Ashes. I might add, that I have not found that from Venetian Talck (I say Venetian, because I have found other kinds of that Mineral more open) from the Lapis Ossifragus, (which the Shops call Ostiocolla) from Muscovia Glass, from pure and Fusible Sand, to mention now no other Concretes; those of my Acquaintance that have try’d have been able by the Fire to separate any one of the Hypostatical Principles, which you will the less scruple to believe, if you consider that Glass may be made by the bare Colliquation of the Salt and Earth remaining in the Ashes of a burnt Plant, and that yet common Glass, once made, does so far resist the violence of the Fire, that most Chymists think it a Body more undestroyable then Gold it self. For if the Artificer can so firmly unite such comparative gross Particles as those of Earth and Salt that make up common Ashes, into a Body indissoluble by Fire; why may not Nature associate in divers Bodies the more minute Elementary Corpuscles she has at hand too firmly to let them be separable by the Fire? And on this Occasion, Eleutherius, give me leave to mention to you two or three sleight Experiments, which will, I hope, be found more pertinent to our present Discourse, than at first perhaps they will appear. The first is, that, having (for Tryals sake) put a quantity of that Fugitive Concrete, Camphire, into a Glass Vessel, and plac’d it in a gentle Heat, I found it (not leaving behinde, according to my Estimate, not so much as one Grain) to sublime to the Top of the Vessel into Flowers: which in Whiteness, Smell, &c. seem’d not to differ from the Camphire it self. Another Experiment is that of Helmont, who in several places affirms, That a Coal kept in a Glass exactly clos’d will never be calcin’d to Ashes, though kept never so long in a